Non-medical fabric face masks can limit the spread of COVID-19
World Health Organization changes its position on the wearing of non-medical fabric face masks.
People should be encouraged to use non-medical fabric face masks, known simply as fabric masks, in situations where they are unable to physical distance beyond one metre – such as in supermarkets, on public transport or in crowded or confined spaces – says the World Health Organization (WHO).
Mask-wearing while out in public is also beneficial in high population density settings like refugee camps, informal settlements and slums, where public health measures such as physical distancing, contact tracing, testing, and isolation and care for suspected or confirmed COVID-19 cases are difficult to implement.
In the updated guidance, the WHO says fabric masks act as a barrier and can prevent the wearer of the mask from infecting others – known as source control – in settings where COVID-19 is known or suspected to be spreading in the community.
It’s the first time the WHO has recommended masks for infection control in the general public, and fabric masks specifically, during the COVID-19 pandemic. Policies mandating their use are already in place across Asia and in places where mask-wearing is not commonplace, such as the Czech Republic and the USA.
Fabric masks protect others from possible infection by the wearer. They are not medical masks, are not tested or standardised and can be homemade. They should contain at least three layers: a water-resistant outer layer, a water-absorbent inner layer, and a mid-layer which acts as a filter.
Medical masks protect the wearer from getting or passing on the virus. They are performance-tested according to international standards looking at breathability and filtration. They are flat or pleated and are also known as surgical or procedural masks.
Respirators are a type of medical-grade mask with a more advanced filtering system. They are used where aerosol generating procedures are performed.
High-quality scientific evidence regarding the effectiveness of masks (both medical and non-medical) for healthy individuals in public places is limited, which meant the WHO didn’t change its position until now.
However, evidence is emerging around the transmission of COVID-19 by some pre-symptomatic (those infected with COVID-19 and not yet displaying symptoms), and asymptomatic (those infected who do not display symptoms) people, who may be unknowingly shedding the virus.
In these cases, wearing fabric masks can prevent seemingly healthy people from passing on the virus in public space. However, they need to be used correctly in order to be effective – with frequent hand hygiene and awareness of the potential harms relating to self-contamination if you keep adjusting your mask.
Given the alarming global shortage of medical masks and respirators, the WHO says these types of masks – which prevent the wearer from getting or passing on COVID-19 – should be reserved and prioritised for health care workers, people with COVID-19 symptoms and those caring for them.
Groups at an increased risk of developing severe COVID-19, such as people over 60 and those with certain pre-existing conditions, should also wear medical masks in situations where they are unable to physical distance from others.
The guidance recommends that all patient-facing health workers working in facilities in areas of known COVID-19 transmission should wear medical-grade masks continuously throughout the day. Health workers working with patients in the community should also consider wearing face masks when distances of one meter cannot be maintained.